Owin：异常：System.ObjectDisposedException：无法访问已处置的对象。对象名称：'System.Net.HttpListenerRequest'

Question

我得到了很多类似下面的日志，有人知道这件事的根本原因吗？这是否与以下代码有关：

// Gets the client IP when hosted in IIS, where HttpContext.Current is not null.
if (httpRequest != null)
    return httpRequest.UserHostAddress;
    
// Gets the client IP when hosted in Owin, where there is no HttpContext.Current by default.
if (!request.Properties.ContainsKey("MS_OwinContext"))
    return null;
    
var context = request.Properties["MS_OwinContext"] as OwinContext;
return context?.Request.RemoteIpAddress;

日志：

Exception: System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'System.Net.HttpListenerRequest'.  at System.Net.HttpListenerRequest.CheckDisposed()  at System.Net.HttpListenerRequest.get_RemoteEndPoint()  at Microsoft.Owin.Host.HttpListener.RequestProcessing.OwinHttpListenerRequest.GetRemoteIpAddress()  at Microsoft.Owin.Host.HttpListener.RequestProcessing.CallEnvironment.get_ServerRemoteIpAddress()  at Microsoft.Owin.Host.HttpListener.RequestProcessing.CallEnvironment.PropertiesTryGetValue(String key, Object& value)  at Microsoft.Owin.Host.HttpListener.RequestProcessing.CallEnvironment.TryGetValue(String key, Object& value)  at Microsoft.Owin.OwinRequest.Get[T](String key)

Answer 1

我之前遇到过类似的问题，发现Request上有一个CancellationToken，你可以查看是否已请求取消。

下面是我的代码，我试图访问Request (OwinRequest) 的LocalPort 并用if 包围它。您可以使用相同的if。

// context.Request.LocalPort will throw ObjectDisposedException if we try to access LocalPort of cancelled
// request, thus the order of conditions in below if is important.
if (context?.Request != null &&
    !context.Request.CallCancelled.IsCancellationRequested &&
    context.Request.LocalPort != null)
{
                requestPort = context.Request.LocalPort.Value;
}